Abstract: In recent years, under the background of energy conservation and emission reduction, major countries in the world have issued mandatory high efficiency distribution transformer standards.Our country issued the new standard GB 20052-2013 in 2013, which was updated on May 29th 2020 and will be enforced in 2021. To meet the updated transformer standards and energy efficiency upgrade, it is important to enhance the magnetic properties of core materials. Baosteel had developed new products B18R055 and B20R060 in the fourth intelligent factory of silicon steel, which were successfully used for grade S15 energy efficiency distribution transformers. The typical properties of B20R060 product were two grades higher than the highest grade of international  silicon steel with the same thickness, and the B18R055 product is the lowest iron loss oriented silicon steel in the world. In this paper, the properties and transformer performance of B18R055 and B20R060 are introduced, expecting favorable for material selection of transformer manufacturers.

Key words: grain oriented electrical steels, development, B18R055, B20R060